At first, the focus was engineering. Then it became obvious that great results do not come from individual brilliance alone. They depend on how a team works together, how engineers collaborate with customers, and how seriously technical excellence is taken. Practices like TDD were not side topics. They were part of what made quality and speed possible.
Later, Silicon Valley added another layer. There, Matthias learned more about business models, future markets, innovation, and how larger organizations can organize product development without suffocating what makes innovation possible in the first place.